A 3D display may be simply defined as an “embodiment of a system reproducing a 3D screen artificially”.
Here, a system includes both a software technique allowing an object to be seen three-dimensionally and hardware implementing contents created by a software technique three-dimensionally. The reason for including even the software area is because, in case of 3D display hardware, contents configured by separate software are separately required for each stereoscopic implementation method.
Also, a virtual 3D display is an embodiment of a system providing stereoscopic sense to a user virtually in planar display hardware by using binocular disparity occurring as humans' eyes are spaced apart by about 65 mm in a horizontal direction among various factors by which users may feel depth. In other words, humans' eyes view slightly different images (strictly speaking, humans' eyes slightly share horizontal spatial information) due to binocular disparity although they view the same object, and when the two images are transmitted to the brain through retina, the brain accurately unite (or merge) to make humans feel depth. On the basis of this phenomenon, a 2D display device is designed to simultaneously display two left and right images and allow the left eye to view the left image and the right eye to view the right image to thus create a virtual stereoscopic sense, implementing a virtual 3D display.
In order to display images of two channels on a single screen of a virtual 3D display hardware device, in most cases, channels are output one by one by changing lines one by one in either horizontal or vertical direction in a single screen. When images of two channels are simultaneously output from a single display device, a right image is transferred to a right eye as it is and a left image is transferred to only a left eye in case of a glassless (or glass-free) scheme in terms of hardware structure. Also, in case of a glass scheme, a right image is covered such that a left eye cannot view it and a left image is covered such that a right eye cannot view it through appropriate respective special glasses.
Although channels are output one by one by changing lines, since a thickness of the lines and a space between lines are as small as 0.1 mm to 0.5 mm, users' eyes cannot recognize it and respective eyes recognize two images of respective channels, as one screen. In this case, however, in comparison to a case of using a 2D screen, an amount of information transferred to the eyes is divided into half for each channel, reducing resolution and user-perceived brightness to half.
A stereoscopic image display method includes a glass type method in which a user wear glasses and a glass-free method in which a user does not wear glasses.
Typical glass-free methods include a lenticular method and a parallax barrier method. In the lenticular method, a lenticular lens plate with cylindrical lenses vertically arranged thereon is installed in front of a display panel.
In the parallax barrier method, two left and right images are alternately disposed at appropriate intervals behind openings corresponding to fine slits included in a parallax barrier, and when the two images are viewed through the openings at a particular timing, the both images are accurately separately viewed. To put it simply, left and right channels are simply blocked by a wall so as to be distinguished, without using an optical technique such as a polarization method.
Meanwhile, in line with the information-oriented age which has recently been rapidly advanced, various utilization methods of display devices have been proposed. For example, a product allowing one screen to be rotated vertically or horizontally so as to be appropriately used for a pertinent purpose has been introduced, which is currently utilized in a display screen for cell phones, a monitor, or the like.
Namely, existing display devices are generally fixed to display only a landscape image in which a horizontal width is greater than a vertical height or a portrait image of the reverse. However, recently, an image display device having a pivot function allowing the device to be rotated to display a landscape image or a portrait image as necessary has been studied. In case of watching movie, or the like, the image display device may operate in a landscape display mode, and in case of an operation for displaying a large amount of information, for example, in case of opening multiple text files and operating them, the image display device may operate in a portrait display mode.